/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package com.architexa.org.eclipse.gef;

import org.eclipse.jface.action.IMenuListener;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.MenuManager;

/**
 * Extends MenuManager to allow populating the menu directly from the manager itself.
 * Using this class is no different than using a standalone <code>MenuManager</code>, and
 * adding a menuAboutToShow listener.
 * 
 * @author hudsonr
 */
public abstract class ContextMenuProvider 
	extends MenuManager
	implements IMenuListener
{

private EditPartViewer viewer;

/**
 * Constructs a context menu for the specified EditPartViewer.
 * @param viewer the editpart viewer
 */
public ContextMenuProvider(EditPartViewer viewer) {
	setViewer(viewer);
	addMenuListener(this);
	setRemoveAllWhenShown(true);
}

/**
 * Called when the menu is about to show. Subclasses must implement this method to
 * populate the menu each time it is shown.
 * @param menu this parameter is actually <code>this</code> object
 */
public abstract void buildContextMenu(IMenuManager menu);

/**
 * Returns the EditPartViewer
 * @return the viewer
 */
protected EditPartViewer getViewer() {
	return viewer;
}

/**
 * @see IMenuListener#menuAboutToShow(IMenuManager)
 */
public void menuAboutToShow(IMenuManager menu) {
	buildContextMenu(menu);
}

/**
 * Sets the editpart viewer. Called during construction.
 * @param viewer the viewer
 */
protected void setViewer(EditPartViewer viewer) {
	this.viewer = viewer;
}

}
